Study of the cyclic oxidation resistance of Al coated ferritic steels with 9 and 12%Cr

Ferritic stainless steels exhibit good oxidation resistance due to formation of a protective chromia scale. However, the protective chromia scale spalled or cracked after the metal substrate, was subjected to repeated thermal cycling oxidation. Aluminide coatings applied by FB-CVD were found to improve the cyclic oxidation resistance of P92 and HCM12 stainless steels. The protective effect depends on the coating properties. The cyclic oxidation resistance of P92 and HCM12 coated with Al was limited by spallation of the alumina scale due to the presence of voids and cavities at the coating-oxide interface. The computer simulation of cyclic oxidation behaviour of uncoated and coated ferritic steels using COSP, DICOSM programs showed the region of the universal cyclic oxidation life map where these substrates were located.